Knowles, who was suspended without pay in June, is charged with 14 counts of illegally recording telephone calls at the sheriff's substation he commanded in Ocoee. His trial is scheduled for later this year.

The internal investigation, conducted by Capt. Buck Buchanan, does not recommend if Knowles should be disciplined. Staff attorney Bill Vose said Sheriff Lawson Lamar will make no decision until the criminal charges are resolved.

Lamar released the investigation after repeated demands from The Orlando Sentinel, which contended the completed investigation was public record. It was conducted separately from the criminal case, which was handled by the Florida Department of Law Enforcement's Orlando office.

In a May 30 interview with Buchanan, Knowles said he recorded a conversation in which he joked with Deputy Julian Fuller.

He also said he recorded a conversation with Brantley Slaughter, a west Orange community activist who had accused several deputies of improper conduct. Knowles said he taped the call because he wanted to investigate Slaughter. Under state statutes, law enforcement officers can tape calls when gathering evidence in a crminal case.

Among the calls Knowles is charged with illegally recording were two conversations with Fuller on Aug. 19, 1983, and a conversation with Slaughter that occurred between Jan. 1 and Feb. 28, 1984.

Knowles said tapes of the calls he recorded were among 16 cassettes seized by FDLE and sheriff's investigators after searching his office.

Knowles told Buchanan he didn't think taping Fuller was illegal ''knowing it was between two friends . . . because there was no criminal intent.''

Knowles denied recording conversations with Undersheriff Larry Shultz and sheriff's Cmdr. Peter Marcus, both of whom he is charged with taping. He also denied making any other tapes besides those of Slaughter and Fuller or authorizing any.

Both probes of Knowles started after electronics expert Kenneth Pearce told FDLE investigators and The Orlando Sentinel in May that he installed a recording device in Knowles' office in August 1983.

In an interview with Buchanan, Pearce said he was approached by former sheriff's Sgt. Fred Crawford about installing the equipment because Knowles was ''having a problem with

Peter Marcus.''

Marcus and Schultz are known to be political enemies of Terry James, jail director, and his brother, Inspector Jere James, both close allies of Knowles within the department.

Pearce said he installed the equipment with Knowles present and showed him how it worked. Crawford was there part of the time, Pearce said.

According to the investigation report, Crawford largely substantiated Pearce's statements in an interview with FDLE agents.

Knowles, however, said he only discussed recording equipment with Crawford, and that Crawford had the equipment installed while he was out. He said he barely knew Pearce.

Knowles said Crawford gave a different story because ''it's a hate factor with Sgt. Crawford . . . I had to let this man go for messing with women.'' Crawford resigned last year after a sheriff's internal investigation concluded that he had sexually harassed female employees.

Knowles refused to take a polygraph test, saying he was upset that FDLE was conducting a criminal investigation and that the case had been publicized.

Bernie Dempsey, Knowles' lawyer, said the release of the report before Knowles' trial was inappropriate. He said he had not seen the report.